A failure in operation of an electronic circuit part, a relay contacting surface, an integrated circuit device such as an IC or an LSI or any other very small electronic part is caused in most cases by a contaminating impurity sticking to the surface.
Contaminating impurities can be roughly divided into the following three:
(1) organic molecules including negative atoms such as oxygen, chlorine or sulfur;
(2) hydrocarbon molecules; and
(3) organic molecules which include both of nitrogen and oxygen.
Since the cause of a failure in operation which takes place is different depending upon the type of the contaminating impurity, it is important and necessary to specify what the contaminating impurity is.
As methods of analyzing a contaminating impurity sticking to the surface of an object, a reflection type infrared absorption method, an ion irradiation mass spectrometry method and a slow electron energy loss analysis method are practically used. However, while those analysis methods are all applied where the analysis surface area for which it is required to perform an analysis is approximately (0.1 mm).sup.2 to (several mm).sup.2, in order to analyze the surface of a chip of a semiconductor device at present, the analysis surface area is required to be on the order lower than (.mu.m).sup.2. Accordingly, any of the analysis methods described above is not suitably used to analyze the surface of an electronic part.
Also a different method is available wherein an electron beam is irradiated upon the surface of a specimen and desorbed molecules are analyzed using a mass spectrograph. In this instance, it is possible to concentrate energy upon a very small region on the order lower than (.mu.m).sup.2 from a relationship of an electron wavelength, and it is possible to analyze the very small region.
From among the conventional analysis methods described above, the reflection type infrared absorption method, the ion irradiation mass spectrometry method and the slow electron energy loss analysis method are not suitable to analyze the surface of an electronic part since the area required for the analysis is large.
The method wherein an electron beam is irradiated and desorbed molecules are analyzed using a mass spectrograph allows an analysis of a very small region. However, the method has a problem in that, where different molecules have an equal mass number (for example, CH.sub.4 and O, CH.sub.4 OH and O.sub.2, and so forth), it cannot be specified what the contaminating impurity is.